lib/chroot.sh: New file

2 files changed, 80 insertions, 0 deletions

diff --git a/lib/chroot.sh b/lib/chroot.sh
new file mode 100644
index 0000000..de3b2f5
--- /dev/null
+++ b/lib/chroot.sh
@@ -0,0 +1,79 @@
+# ProteanOS Development Kit
+# lib/chroot.sh
+# Functions for setting up isolated file system environments
+#
+# Copyright (C) 2014  Patrick "P. J." McDermott
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+[ "x${_CHROOT_SM+set}" = 'xset' ] && return 0
+_CHROOT_SM=1
+
+use profile
+
+chroot_mount()
+{
+	local root="${1}"
+	local arch=
+	local plat=
+	local fs=
+	local dir=
+	local fstype=
+	local options=
+
+	arch="$(cat "${root}/etc/proteanos_arch")"
+	plat="$(cat "${root}/etc/proteanos_plat")"
+
+	while read fs dir fstype options; do
+		mount -t "${fstype}" -o "${options}" "${fs}" "${root}/${dir}"
+	done <<-EOF
+		$(profile_get_fstab "${arch}" "${plat}")
+		EOF
+}
+
+chroot_umount()
+{
+	local root="${1}"
+	local arch=
+	local plat=
+	local fs=
+	local dir=
+	local fstype=
+	local options=
+
+	arch="$(cat "${root}/etc/proteanos_arch")"
+	plat="$(cat "${root}/etc/proteanos_plat")"
+
+	while read fs dir fstype options; do
+		# umount sometimes complains that the /dev file system is busy.
+		# Here's a kludge to try to handle that.  We better make sure
+		# bind mounts get unmounted; otherwise, `rm -Rf ${root}` can be
+		# painful.
+		while ! umount "${root}/${dir}"; do
+			sleep 1
+		done
+	done <<-EOF
+		$(profile_get_fstab "${arch}" "${plat}" | sed -n '1!G;h;$p')
+		EOF
+}
+
+chroot_exec()
+{
+	local root="${1}"
+	shift 1
+
+	chroot_mount "${root}"
+	chroot "${root}" "${@}"
+	chroot_umount "${root}"
+}
diff --git a/lib/local.mk b/lib/local.mk
index 2fc6dfd..1ed0c31 100644
--- a/lib/local.mk
+++ b/lib/local.mk
@@ -6,5 +6,6 @@ pkgdata_sources = \
 	lib/control.sh \
 	lib/feed.sh \
 	lib/pkg.sh \
+	lib/chroot.sh \
 	lib/cmd.sh \
 	lib/profile.sh